code: def _get_contigs_from_loco_df(df: pd.DataFrame) -> pd.Series:
      return df.index.get_level_values(1).unique()
  
file_path: glow/python/glow/wgr/wgr_functions.py
imports: from glow import glow
  import pandas
  import numpy
  from pyspark import SparkContext
  from pyspark.sql import DataFrame, Row, SparkSession, SQLContext
  from typeguard import check_argument_types, check_return_type
  from typing import Any, Dict, List
  from nptyping import Float, NDArray
  from .ridge_reduction import RidgeReduction
  from .ridge_regression import RidgeRegression
  from .logistic_ridge_regression import LogisticRidgeRegression
label_desc: Use image node_id 1 for calling a global function with example usage: _get_contigs_from_loco_df(df) and returns: df